In a sauce pan combine oil and rice. Cook, stirring, over medium heat until rice begins to brown. Add tomatoes, chiles, water, onions, chicken bullion and taco seasoning. Stir to combine. Bring to a boil. Cover and reduce to a simmer. Continue simmering over low heat until all liquid is absorbed.
If you have cooked ground beef in your freezer, you can add some defrosted meat when you add tomatoes. You can also add canned beef or canned chicken. Spanish Rice is a fantastic burrito filler with cooked pinto or black beans. It also makes a great meal with just beans and some sour cream.
Notes: To make this for less, I buy the taco seasoning in bulk at Sam's Club. I also get the dried onions (large container) and rice (50 lbs) there. I buy Knorr Chicken Bullion powder in a 2.2lb container at Walmart for just under $5. I also get the diced tomatoes at Walmart for less than $1 a can (usually about .89 each). I buy my oil there as well.
I buy corn on sale at the case-lot sales for .50 a can, though you can sometimes get it for even less by combining sales and coupons. I buy the olives for $1.06 a can at Sam's Club; we only have those occasionally with this meal. Sam's Club also has a great price on tortillas.